1. Field of the Invention
The present invention relates to a probe for providing micro liquid drops. Particularly, it can form a probe array for providing micro liquid drops, especially for sample or reagent dispensing in which, the structure of each probe is strong, the liquid storing capacity is high, its liquid output is stable, it is easier to manufacture the guiding flow ways, and it is easy to clean.
2. Description of the Prior Art
Referring to FIGS. 10 and 11, it shows a conventional probe structure 90 on a laboratory carrier tray 80. This conventional probe structure 90 has an upper end and a lower end. It further comprises:
a limiting head 91 disposed on the upper end of the probe structure 90 for hanging on the laboratory carrier tray 80;
a probe body 92 extending from the limiting head 92 toward the lower end of the probe structure 90 so that the probe body 92 can be moved on the laboratory carrier tray 80; and
a liquid providing end 93 formed at the lower end of on the probe structure 90 and connecting with the probe body 92. This liquid providing end 93 has a liquid releasing port 931 at the lower end of the probe structure 90. The liquid providing end 93 has an axial open channel 932 and a storage portion 933. The axial open channel 932 has a width W. The function of the storage portion 933 is to store a working fluid 70 (not shown) therein.
However, the disadvantages of the conventional probe structure 90 can be listed as follows:
[1] The structure of the liquid providing end is weak. In order to release the working fluid 70, the liquid providing end 93 has to hit another object (such as a laboratory sample array carrier or the like). Because the liquid providing end 93 is split into two parts, its structure is weaker, especially at the hitting moment where it might influence the width W (getting wider or deforming). As a result, the volume of the out liquid each time will be slightly altered and becomes unstable.
[2] The liquid storing capacity is limited. The volume of storing portion 933 of the conventional probe structure 90 is relatively small, so its liquid storing capacity is limited. If the stored liquid is not sufficient, the user has to re-fill several times during an experiment or testing. Thus, it will cause unnecessary interruption and delay.
[3] The output liquid is unstable. The volume of each output droplet is gradually reduced meaning that the output liquid is unstable. At the beginning, the droplet is larger, but at the end, the droplet becomes smaller and will decrease the accuracy of the experiment or the testing. In addition, if just increasing the width of the axial open channel 932 too much, the capillarity effect will be reduced and the output droplet cannot remain constant.
[4] The surface of the axial open channel is too rough and the channel's size cannot be too small. The axial open channel 932 usually is manufactured by wire cut electrical discharging machining, so the surface of the axial open channel 932 is rough. However, due to the wire's tensile strength and melting point limitation, the diameter of the wire cannot be too small. In addition, there are two discharging gaps on both sides of the wire, so the minimum width of the axial open channel 932 cannot be too narrow. Thus, the rough surface and the channel's size will influence the flowing condition.
[5] It is hard to clean due to the liquid's viscosity and the narrow space of the open channel 932 and the storage portion 933, the liquid is easy to stick inside. Such liquid residue needs to be completely washed out. In fact, it's hard to clean.